If I knew for certain that I should die next week, I would still be able to sit at my desk all week and study with perfect equanimity, for I know now that life and death make a meaningful whole.
Prayer obtains what it is due to obtain — not what I personally want to obtain, which is different. It is useful that islands of prayer exist in the world, even if they are composed of only one person, or two, or three, or four.